Question

Which application layer protocol is used to retrieve emails from a remote server to a local client?

• A. SMTP
• B. POP3
• C. SNMP
• D. FTP

Hint:

Think of SMTP as the Postman who takes your letter and puts it in the recipient's mailbox. Think of POP3 as the Recipient going to the post office to pick up their mail.

Answer 1

The Correct Option is B

Concept:
Email systems utilize specific protocols for different tasks. These are generally divided into "Push" protocols (for sending) and "Pull" protocols (for receiving/retrieval).

Step 1: Understanding SMTP (Simple Mail Transfer Protocol).
SMTP is a "Push" protocol. Its primary role is to move an email from the sender's client to the sender's mail server, and then from server to server across the internet until it reaches the recipient's mail server. It cannot be used to "download" or "pull" mail from a server to a local device.

Step 2: Understanding POP3 and IMAP.
To retrieve messages from a server, a "Pull" protocol is required.
• POP3 (Post Office Protocol version 3): This protocol downloads emails from the server to the local client and, by default, deletes them from the server. It is ideal for users who access mail from a single device.
• IMAP (Internet Message Access Protocol): This is a more modern alternative that synchronizes the client with the server, allowing mail to be viewed on multiple devices.

Step 3: Conclusion.
Among the given options, POP3 is the only one designed for the retrieval of email. SNMP is for network management, and FTP is for general file transfers.